ORCID Profile
0000-0002-3859-5017
Current Organisation
Murdoch University
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Publisher: Wiley
Date: 10-2023
DOI: 10.1002/GPS.6016
Publisher: Elsevier BV
Date: 02-2023
DOI: 10.1016/J.BBR.2022.114108
Abstract: Lifestyle factors such as physical activity and optimal sleep are associated with better cognition and lower levels of Alzheimer's disease (AD) biomarkers, including brain beta-amyloid (Aβ) burden. We utilised cross-sectional data from the Australian Imaging, Biomarkers and Lifestyle (AIBL) study to determine whether self-reported physical activity (measured via the International Physical Activity Questionnaire) moderates the relationship between self-reported sleep (measured via the Pittsburgh Sleep Quality Index), cognition, and brain Aβ. Participants were 349 community-dwelling cognitively normal older adults (75.3 ± 5.7 years), all of whom underwent comprehensive cognitive assessment. Data from a subset of participants (n = 201) were used for analyses with brain Aβ burden (measured by positron emission tomography) as the outcome. Physical activity moderated the relationship between sleep duration and episodic memory (β = -0.10, SE =0.03, p = .005), and sleep efficiency and episodic memory (β = -0.09, SE =0.04, p = .011), such that greater amounts of physical activity mitigated the impact of suboptimal sleep duration and efficiency on episodic memory. Physical activity also moderated the relationship between sleep duration and brain Aβ (β = -0.13, SE =0.06, p = .031), and overall sleep quality and brain Aβ (β = 0.13, SE =0.06, p = .027). Our findings suggest that physical activity may play an important role in the relationship between sleep and cognitive function, and brain Aβ.
Publisher: Springer Science and Business Media LLC
Date: 27-01-2023
DOI: 10.1186/S13195-023-01170-4
Abstract: Wide evidence suggests that physical activity (PA) confers protection against Alzheimer’s disease (AD). On the other hand, the apolipoprotein E gene ( APOE ) ε4 allele represents the greatest genetic risk factor for developing AD. Extensive research has been conducted to determine whether frequent PA can mitigate the increased AD risk associated with APOE ε4. However, thus far, these attempts have produced inconclusive results. In this context, one possible explanation could be that the influence of the combined effect of PA and APOE ε4 carriage might be dependent on the specific outcome measure utilised. Main body. In order to bridge these discrepancies, the aim of this theoretical article is to propose a novel model on the interactive effects of PA and APOE ε4 carriage on well-established mechanisms underlying AD. Available literature was searched to investigate how PA and APOE ε4 carriage, independently and in combination, may alter several molecular pathways involved in AD pathogenesis. The reviewed mechanisms include amyloid beta (Aβ) and tau deposition and clearance, neuronal resilience and neurogenesis, lipid function and cerebrovascular alterations, brain immune response and glucose metabolism. Finally, combining all this information, we have built an integrative model, which includes evidence-based and theoretical synergistic interactions across mechanisms. Moreover, we have identified key knowledge gaps in the literature, providing a list of testable hypotheses that future studies need to address. We conclude that PA influences a wide array of molecular targets involved in AD neuropathology. A deeper understanding of where, when and, most importantly, how PA decreases AD risk even in the presence of the APOE ε4 allele will enable the creation of new protocols using exercise along pharmaceuticals in combined therapeutic approaches.
Publisher: Elsevier BV
Date: 11-2021
Publisher: Frontiers Media SA
Date: 05-10-2023
Publisher: Wiley
Date: 19-01-2023
DOI: 10.1002/ALZ.12950
Abstract: The current study investigated the association between objectively measured physical activity and cognition in older adults over approximately 8 years. We utilized data from 199 cognitively unimpaired in iduals from the Australian Imaging, Biomarkers and Lifestyle (AIBL) study, aged ≥60. Actigraphy was used to measure physical activity (intensity, total activity, and energy expenditure) at baseline. Cognition was assessed using a comprehensive cognitive battery every 18‐months. Higher baseline energy expenditure predicted better episodic recall memory and global cognition over the follow‐up period ( p = 0.031 p = 0.047, respectively). Those with higher physical activity intensity and greater total activity also had better global cognition over time (both p = 0.005). Finally, higher total physical activity predicted improved episodic recall memory over time ( p = 0.022). These results suggest that physical activity can preserve cognition and that activity intensity may play an important role in this association. Greater total physical activity predicts preserved episodic memory and global cognition. Moderate intensity physical activity ( .7 metabolic equivalents of task [MET]) predicts preserved global cognition. Expending 373 kilocalories per day may benefit episodic memory and global cognition.
Publisher: Annual Reviews
Date: 09-05-2022
DOI: 10.1146/ANNUREV-CLINPSY-072720-014213
Abstract: Is the field of cognitive aging irretrievably concerned with decline and deficits, or is it shifting to emphasize the hope of preservation and enhancement of cognitive function in late life? A fragment of an answer comes from research attempting to understand the reasons for in idual variability in the extent and rate of cognitive decline. This body of work has created a sense of optimism based on evidence that there are some health behaviors that lify cognitive performance or mitigate the rate of age-related cognitive decline. In this context, we discuss the role of physical activity on neurocognitive function in late adulthood and summarize how it can be conceptualized as a constructive approach both for the maintenance of cognitive function and as a therapeutic for enhancing or optimizing cognitive function in late life. In this way, physical activity research can be used to shape perceptions of cognitive aging.
No related grants have been discovered for Kelsey Sewell.